A high voltage DC ripple power supply sampling circuit

Abstract

The present invention provides a high-voltage DC ripple power supply sampling circuit, which belongs to the technical field of high-voltage DC ripple power supplies. The circuit comprises a high-voltage DC ripple power supply, a high-voltage DC ripple power supply controller, an operational amplifier U1, an operational amplifier U2, a sampling resistor and a sampling capacitor. A very concise circuit is used to realize direct access of a high-voltage voltage to the operational amplifier, thereby realizing sampling and separation of a kilovolt-level DC voltage and a ripple, and collecting a high-frequency AC voltage with high quality, thereby making it possible for the high-voltage DC ripple power supply to accurately control the ripple amplitude and frequency at the load end.

Description

Technical Field

[0001] The invention relates to the technical field of high-voltage direct current ripple power supplies, and in particular to a high-voltage direct current ripple power supply sampling circuit. Background Art

[0002] According to domestic and international industry standards, a high-voltage DC voltage with AC ripple will be added to the DUT during the high-voltage system test of electric vehicles. This test relies on ripple power supply technology, which can achieve the characteristics of superimposing ripples of different frequencies on the high-voltage DC voltage. However, in order to accurately control the amplitude and frequency of the AC ripple, the high-frequency AC voltage and the high-voltage DC voltage must be separated and collected.

[0003] The existing high-voltage DC ripple power supply can separate and collect AC ripple, but the overall solution and circuit are relatively complex. In addition, because the output DC voltage amplitude of the high-voltage DC ripple power supply is nearly 1,000 volts and the ripple is only tens of volts, the collected AC ripple signal value is very small and is easily interfered and submerged by noise. Figure 1 As shown, Figure 2 The output voltage of the high-voltage DC ripple power supply includes a DC voltage of 1000V or higher, and an AC ripple of several tens of VACpp is superimposed on the DC voltage. After this voltage signal passes through a high-resistance sampling circuit, the output signal is as follows Figure 3 , the DC and AC components are reduced by 100 times in the same proportion, and a 10VDC+0.4VACpp signal is obtained. After being processed by the AC / DC separation circuit, Figure 4 The signal shown only has 0.4VACpp AC signal. As mentioned above, due to the large difference in the amplitude of the AC and DC components of the output voltage of the high-voltage DC ripple power supply, the AC component amplitude finally collected is very small, with a maximum value of only 400mVACpp, which is easily interfered or submerged by noise. In addition, the voltage Hall sampling method also has very high requirements for the Hall. Based on the above problems, the present invention proposes a simple and efficient sampling circuit. Summary of the invention

[0004] The purpose of the present invention is to provide a high-voltage DC ripple power supply sampling circuit, which can not only complete the sampling and separation of kilovolt-level DC voltage and ripple, but also has a simple circuit and is easy to implement.

[0005] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0006] A high-voltage DC ripple power sampling circuit comprises a high-voltage DC ripple power supply, a high-voltage DC ripple power supply controller, an operational amplifier U1, an operational amplifier U2, a sampling resistor and a sampling capacitor; the positive electrode of the output voltage Uo of the high-voltage DC ripple power supply is connected to the inverting input terminal of the operational amplifier U1 through the sampling resistor and the sampling capacitor, the negative electrode of Uo is connected to the non-inverting input terminal of the operational amplifier U1 through the sampling resistor and the sampling capacitor, the output terminal of the operational amplifier U1 is connected to the inverting input terminal of the operational amplifier U2, and the output terminal of the operational amplifier U2 is connected to the high-voltage DC ripple power supply controller.

[0007] Furthermore, the output voltage of the high voltage DC ripple power supply Positive electrode and sampling resistor One end connected, The other end is connected to one end of the sampling capacitor. The other end is connected to the sampling resistor One end of the connection, The other end is connected to the inverting input of the operational amplifier U1, and the output voltage of the high-voltage DC ripple power supply Negative electrode and sampling resistor One end of the connection, The other end is connected to the sampling capacitor One end of The other end is connected to the sampling resistor One end of the connection, The other end is connected to the non-inverting input of the operational amplifier U1, and the non-inverting input of the operational amplifier U1 is connected to the non-inverting input of the operational amplifier U1 through the sampling resistor Grounded, a sampling resistor is connected between the inverting input and the output ;

[0008] A sampling resistor is connected between the output terminal of the operational amplifier U1 and the inverting input terminal of the operational amplifier U2. The non-inverting input of operational amplifier U2 is connected through the sampling resistor Grounded, a sampling resistor is connected between the inverting input and the output .

[0009] Furthermore, the transfer function is:

[0010]

[0011] in, are the resistance values ​​of the sampling resistors, ; , are the capacitance values ​​of the sampling capacitors respectively; is the output voltage of the high voltage DC ripple power supply, is the voltage at the output of operational amplifier U2.

[0012] Furthermore, the sampling capacitor , They are all high-voltage, high-frequency, low-inductance capacitors.

[0013] Furthermore, the sampling resistor , , , sampling capacitor .

[0014] The advantages of the present invention are: using a very simple circuit to directly connect the high voltage to the operational amplifier, achieving the sampling and separation of the kilovolt-level DC voltage and the ripple, collecting the high-frequency AC voltage with high quality, and making it possible for the high-voltage DC ripple power supply to accurately control the ripple amplitude and frequency of the load end;

[0015] Increasing the sampling amplitude of the AC component by 25 times or more greatly improves the anti-interference ability of the sampling;

[0016] It enables 10Hz-150Hz AC ripple to achieve precise output control of amplitude and phase, making the system safer. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a high voltage DC ripple power supply sampling circuit commonly used in existing projects;

[0018] Figure 2 This is the output voltage waveform of the high voltage DC ripple power supply.

[0019] Figure 3 for Figure 1 Uosample signal waveform in the circuit;

[0020] Figure 4 for Figure 1 Usample signal waveform in the circuit;

[0021] Figure 5 It is a schematic diagram of a high-voltage DC ripple power supply sampling circuit system of the present invention;

[0022] Figure 6 The voltage across the high-voltage DC ripple power supply sampling circuit C1 of the present invention;

[0023] Figure 7 The voltage across the high-voltage DC ripple power supply sampling circuit C2 of the present invention;

[0024] Figure 8 The waveform of the output signal Usample of the high-voltage DC ripple power supply sampling circuit of the present invention;

[0025] Fig. 9 This is the Bode diagram of the high-voltage DC ripple power supply sampling circuit of the present invention. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0027] This embodiment proposes a high-voltage DC ripple power supply sampling circuit. Please refer to the circuit diagram Figure 5 , including a high-voltage DC ripple power supply, a high-voltage DC ripple power supply controller, an operational amplifier U1, an operational amplifier U2, a sampling resistor , … and sampling capacitor , .

[0028] Output voltage of high voltage DC ripple power supply Positive electrode and sampling resistor One end connected, The other end is connected to one end of the sampling capacitor. The other end is connected to the sampling resistor One end of the connection, The other end is connected to the inverting input of the operational amplifier U1, and the output voltage of the high-voltage DC ripple power supply Negative electrode and sampling resistor One end of the connection, The other end is connected to the sampling capacitor One end of The other end is connected to the sampling resistor One end of the connection, The other end is connected to the non-inverting input of the operational amplifier U1, and the non-inverting input of the operational amplifier U1 is connected to the non-inverting input of the operational amplifier U1 through the sampling resistor Grounded, a sampling resistor is connected between the inverting input and the output .

[0029] A sampling resistor is connected between the output terminal of the operational amplifier U1 and the inverting input terminal of the operational amplifier U2. The non-inverting input of operational amplifier U2 is connected through the sampling resistor Grounded, a sampling resistor is connected between the inverting input and the output .

[0030] , It is a high-voltage, high-frequency, low-inductance capacitor with specification model STM-1000V-1uF±10%-L37*W31*H22-screw mounting.

[0031] The transfer function of the above high voltage DC ripple power supply sampling circuit is:

[0032]

[0033] in, are the resistance values ​​of the sampling resistors, ; , are the capacitance values ​​of the sampling capacitors respectively; is the output voltage of the high voltage DC ripple power supply, is the voltage at the output of operational amplifier U2.

[0034] The size of the resistance and capacitance of the resistor is Figure 5 The parameters shown are sampling resistors , , , , , sampling capacitor .

[0035] At this time, the sampling capacitor Please refer to the voltage UC1 at both ends Figure 6 , is a stable DC voltage of 500V, the sampling capacitor Please refer to the voltage UC2 at both ends Figure 7 , is a stable DC voltage of 500V, and the output signal is the output voltage of the operational amplifier U2 Please refer to the waveform Figure 8 , for AC voltage, achieving high-quality collection and separation of DC and AC.

[0036] Fig. 9 This is the Bode diagram of the high-voltage DC ripple power supply sampling circuit of this embodiment. It can be seen that it has good high-pass characteristics and small phase shift in a very wide frequency range above 5 Hz, and has very good performance.

[0037] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A high voltage DC ripple power supply sampling circuit, characterized in that: It includes a high-voltage DC ripple power supply, a high-voltage DC ripple power supply controller, an operational amplifier U1, an operational amplifier U2, a sampling resistor and a sampling capacitor; the positive electrode of the output voltage Uo of the high-voltage DC ripple power supply is connected to the inverting input terminal of the operational amplifier U1 through the sampling resistor and the sampling capacitor, the negative electrode of Uo is connected to the inverting input terminal of the operational amplifier U1 through the sampling resistor and the sampling capacitor, the output terminal of the operational amplifier U1 is connected to the inverting input terminal of the operational amplifier U2, and the output terminal of the operational amplifier U2 is connected to the high-voltage DC ripple power supply controller; Output voltage of high voltage DC ripple power supply Positive electrode and sampling resistor One end connected, The other end is connected to one end of the sampling capacitor. The other end is connected to the sampling resistor One end of the connection, The other end is connected to the inverting input of the operational amplifier U1, and the output voltage of the high-voltage DC ripple power supply Negative electrode and sampling resistor One end of the connection, The other end is connected to the sampling capacitor One end of The other end is connected to the sampling resistor One end of the connection, The other end is connected to the non-inverting input of the operational amplifier U1, and the non-inverting input of the operational amplifier U1 is connected to the non-inverting input of the operational amplifier U1 through the sampling resistor Grounded, a sampling resistor is connected between the inverting input and the output ; A sampling resistor is connected between the output terminal of the operational amplifier U1 and the inverting input terminal of the operational amplifier U2. The non-inverting input of operational amplifier U2 is connected through the sampling resistor Grounded, a sampling resistor is connected between the inverting input and the output ; The transfer function is: in, are the resistance values ​​of the sampling resistors, ; , are the capacitance values ​​of the sampling capacitors respectively; is the output voltage of the high voltage DC ripple power supply, is the voltage at the output of operational amplifier U2.

2. The high-voltage DC ripple power supply sampling circuit according to claim 1, characterized in that: Sampling capacitor , They are all high-voltage, high-frequency, low-inductance capacitors.

3. The high-voltage DC ripple power supply sampling circuit according to claim 1, characterized in that: Sampling resistor , , , sampling capacitor .

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